The current method for reading barcode labels at a distance is to produce a barcode symbology with an X dimension (width of the narrow bar) which is suitable for the laser scanner to interpret. As an example, a Symbol Technology (Bohemia, New York) LS 3010 ALR laser scanner can read barcodes at varying distances depending upon the X dimension of the narrow bar of the symbology.
Where the distances from which a barcode must be read vary widely, it has been difficult to get a reading from a single line of barcode at all distances. In warehouse applications where labels are scanned at varying distances, for example, a bottom shelf at four feet and a top shelf at twenty-five feet, many different sized labels and symbology densities are required. To supply these as individual labels has provided to be costly and inflexible when a change in distance is required.
A scanner has some capability of reading the reflected light at varying distances from a scanning of a barcode but there is an optimum distance from each density of barcode. Typically, the correct X dimension at four feet is forty mils, at fifteen feet is seventy mils, at seventy feet is one hundred mils and twenty-five feet and up is one hundred fifty mils. However, until the present invention, the industry has not developed a method or procedure for providing a barcode having different scanning distances in a single label.